In this work, a simple method for fabricating Cu2ZnSnSe4 (CZTSe) thin film by ion-beam sputtering without post-selenization is proposed. The influence of annealing temperature on the composition, the microstructure, the morphology, the electrical and optical properties of CZTSe thin films has been established. The relatively low annealing temperature of 400 degrees C is considered as very positive for obtaining the optimized Cu-poor and Zn-rich CZTSe films with pure CZTSe phase, high crystallinity, P-type conduction and ideal optical band-gap. These interesting features have been used in the prototype photovoltaic devices with a conversion efficiency of 4.67%. These are the first results concerning the use of ion-beam sputtering CZTSe films for photovoltaic application and further improvement of device performance is expected. (C) 2016 Elsevier Ltd. All rights reserved.